There were some positive results returned by the NCI-Cornell-Mikovits team using another method that looked for antibody reactions to these agents.
Dr. Francis Ruscetti’s NCI lab tested serum from the coded samples using a flow cytometry-based assay slightly modified from the one he reported in the original 2009
Science paper.
The team detected antibodies in human serum but when the code was broken, it revealed equal numbers of CFS cases and healthy controls had these antibodies – nine in each group, or six percent of the subjects.
The paper states, “The serology results are more difficult to address given that the assay cannot be validated with plasma from humans with confirmed XMRV or MLV infection. We posit that positive results represent either nonspecific or cross-reactive binding and note that irrespective of explanation, a positive signal does not correlate with case status.”
Nonspecific, cross-reacting antibodies are common and can be the bane of many diagnostic serology platforms.
When serology assays for HIV were first developed, serum from healthy, non-HIV infected people sometimes contained antibodies that reacted with HIV proteins in the assay.
Blood transfusion studies showed that this non-specific antibody pattern did not correlate with transmission of HIV.[5]
It is this type of non-specific reaction that has led to development of HIV screening tests based on antibody testing; positive results from such tests are followed with other testing methods considered to be confirmatory.
To avoid drawing incorrect conclusions about the presence of virus based on the antibody reaction alone, it is imperative to use appropriate control experiments in parallel.
In the 2009 study and this multicenter study, a monoclonal antibody produced from a rat (7C10 rat monoclonal antibody) was used in the tests.
However, this particular antibody has been shown to cross-react with a number of other different viruses when it was originally produced in the early 1980s.[6]
As the authors indicate in the mBio paper, the fact that the positive antibody signal was found in equal numbers of CFS case and healthy control subjects’ serum is strong evidence that it is a sign of nonspecific cross reactivity with no clinical relevance.
It is also worth noting that study authors agreed in advance that the only “subjects with two positive results in the same sample type were considered positive for XMRV/pMLV.”
The 18 samples that tested positive by this method did not meet the stated standard for a “positive” result as agreed to by all the authors.
The De-discovery of XMRV:
http://www.research1st.com/2012/09/18/the-de-discovery-of-xmrv/